Battery-powered computing devices, such as mobile devices, have become commonplace. A typical mobile device operates over a wide performance range according to workload requirements. Different performance ranges are conventionally mapped to different operating modes, with power consumption proportionally related to performance. For example, in a low-power mode, the mobile device may provide a small amount of computational capacity, such as to maintain radio contact with a cellular tower and consume a relatively low amount of power. In a high-performance mode, the mobile device may be subject to high processing intensity tasks such as gaming or web browsing, and therefore consume a relatively high amount of power.
Processor cores within System on Chip (SoC) designs generally utilize more power as performance increases due to an increase in clock frequency and/or usage of additional logic elements. Increasing battery life is important to users of mobile devices that operate on battery power, sometimes for extended periods of time. Accordingly, there is a need for efficient, low power systems that deliver scalable computational capacity with diminishing energy cost.